Scouring pad

ABSTRACT

AN ARTICLE OF MANUFACTURE COMPRISING A SCOURING PAD CONTAINING A CLEANSING COMPOSITION WHEREIN THE SAID CLEANSING COMPOSITION CONTAINS SOAP, HARD-WATER-SENSITIVE OR SOAP-SENSITIVE DETERGENT AND AN ALPHA SULFO FATTY ACID OR ITS MONO-OR DI-SALTS.

United States Patent 3,585,144 SCOURING PAD Lee R. Schiltz, Harvey, andKeith L. Johnson, Matteson, Ill., assignors to Swift & Company, Chicago,Ill. No Drawing. Filed Jan. 19, 1967, Ser. No. 610,242 Int. Cl. Clld17/04 U.S. Cl. 252-91 7 Claims ABSTRACT OF THE DISCLOSURE An article ofmanufacture comprising a scouring pad containing a cleansing compositionwherein the said cleansing composition contains soap,hard-water-sensitive or soap-sensitive detergent and an alpha sulfofatty acid or its monoor di-salts.

This invention relates to a non-defoaming scouring pad. Morespecifically, the invention concerns scouring pads comprising plastic ormetal wool or mesh impregnated with a cleaning composition and which arecapable of general use in water of any degree of hardness.

The utility of scouring pads in the cleaning of pots and pans or othercooking utensils having dried-on or baked-on, hard-to-remove solidmaterials or grease is well known. Usually, these pads are utilized inthe dishpan to clean the pots, pans, and heavily soiled utensils afterthe lightly soiled plates and dishes have been washed and removed fromthe dishpan. In using the soap impregnated pad to clean the greasy potsand pans, the antagonistic effect of the soap and the detergent causesgreatly reduced foam height and the formation of a greasy scum on top ofthe water which in turn forms a film on the pots and pans which isdifficult to rinse or remove. In addition the defoaming effect of thecalcium soap formed by the reaction of the hard water salts generallypresent in domestic water supplies with the scouring soap also acts todefoam the suds remaining in the dishpan, revealing the aestheticallyundesirable dirty dishwater to the eyes of the housewife. This conveysto the housewife the general sense of uncleanliness which she does nothave if the dishpan is covered with a nice white layer of suds. Inaddition to this, it is mentioned that the dissipation of the suds isindicative in thought, if not in fact, of a lack of adequate cleaningability on the part of the detergent used to initially wash the dishes,the soap pad used, or both.

Detergents by themselves do not greatly defoam suds or cause curdformation in the presence of hard water. However a 100% active detergentformulation in the scouring pad is technologically difficult andeconomically inappropriate. Since detergents, in general, are soexpensive to manufacture, a premium price must be obtained when they aresold alone or as the sole active component. Hence, most commercialscouring pads comprise inexpensive soaps either alone or in combinationwith a small amount of detergent. Where soft water is available,scouring pads containing large amounts of soap may be used withcomparatively little defoaming or curd formation. However, in regionswhere only hard water is available, at least a portion of the soap inthe pad is converted into a calcium soap which precipitates in the formof sticky curds. These curds not only have no cleansing properties, butconstitute impurities that must be dispersed by a part of theunconverted soap which is then not available for cleansing.

Several attempts to alleviate the above-mentioned problems have not metwith success. The use of alcohol sulfates, alkyl aryl sulfonates,various lime soap dispersants and other synthetic materials have failedto prevent defoaming or curd formation. In situations where it has beenproposed to overcome the disadvantages of soaps by mixing them withcertain synthetic detergents or dispersing agents which are hard-Waterresistant, it has been shown that these proposals are not entirelysatisfactory.

It is, therefore, an object of this invention to provide a scouring padcapable of functioning adequately in water having any degree ofhardness.

Another object of the present invention is the production of a scouringpad which does not substantially defoam detergent suds.

Additional objects, if not specifically set forth herein, will bereadily apparent to those skilled in the art from a reading of thedetailed description of the invention which follows.

It has now been discovered that the incorporation of certain alpha sulfofatty acids or their mono or disalts into a soap, a hard-water-sensitivedetergent, or soapdetergent formulations results in a composition which,in combination with the scouring material, i.e., metal or plastic woolor mesh, or sponges or sponge Wool combinations, successfully alleviatesthe aforementioned difficulties. The alpha sulfo fatty acids or theirsalts were found to be superior in that it is believed that aftermicelle formation the substance is essentially water insoluble. On theother hand, other sulfo derivatives, such as esters of alpha sulfo fattyacids, are unsuitable for several reasons, one of which is that they areextremely soluble and leach out of the scouring pad. An added feature ofthe alpha sulfo fatty acids is that they are biodegradable and possessno irritating qualities. Such compositions may readily be treated withcertain bacteria to the extent that their detergent or surface activeproperties can be destroyed and hence they do not produce foamingproblems in sewage or other disposal systems.

More specifically, it has been discovered in accordance with the presentinvention that by mixing an ordinary soap, soap-sensitive detergent or ahard-water-sensitive detergent, or a combination of these, with analkali metal, alkaline earth metal, or ammonium, monoor di-salt of thealpha sulfo fatty acid or the free acid, an efficient composition isobtained which when dispersed throughout a metal or plastic scouringpad, results in a superior cleansing pad quite suitable for use in hardwater. It should be pointed out that the alpha sulfo composition may bean essentially pure compound or a mixture thereof, such as a mixture ofthe monoand di-salt or mixtures of various metal acids, i.e., sodium andpotassium salts, etc.

Generally speaking, the amount of alpha sulfo compound will be presentin an amount of about 2 to about 25 percent by weight of the totalcleansing composition. Preferred results were obtained using 10 to 15percent by weight of the alpha sulfo component; however, even amountsabove 25 percent were useful, but the additional cost did not warranttheir presence in such high quantities. Various binders such as wax, aswell as rust inhibitors, coloring agents, mold or fungicidal inhibitors,and/or fillers may be incorporated into the cleansing composition priorto impregnation of the steel wool or like-metal scouring pad.

"Generally speaking, the proportions of the soap or thehard-water-sensitive detergent and the alpha sulfo fatty acid or saltused in the cleansing composition may vary in the manner previouslydescribed; the preferred proportions to be employed being dependentlargely upon the hardness of the water in which the scouring pad is tobe used. By mixing as little as about 2 parts by weight of the sulfofatty acid or its salt with about 98 parts by weight of a soap, acomposition is produced which can be used in moderately hard waterwithout the production of curds. However, in order to produce acomposition which is noticeably superior in its ability to not alfectthe foam nor 3 produce curds, it is preferred to use at least about 5parts by weight of the sulfo component for each 95 parts by weight ofsoap or hard-water-sensitive detergent.

Even in extreme conditions, it has been found that it is unnecessary touse a greater proportion of sulfo component than corresponding to equalparts by weight of sulfo component and soap. For washing in water ofmoderate hardness, i.e., water of hardness corresponding to about 200p.p.m. of CaCO or below, a composition containing parts by weight of oneor more of the sulfo components and about 90 parts by weight of soap isgenerally satisfactory. When exceedingly hard waters are to beencountered, the amount of sulfo component is preferably increasedcorrespondingly. For example, for general scouring purposes in water of400 p.p.m. hardness compositions containing parts by weight of one ormore of the sulfo components for each 80 parts by weight of soap areordinarily satisfactory. In some cases, however, it s advantageous touse in water of this hardness a composition in which the alpha sulfocomponent or components are present in the proportions of about parts byweight for each 70 parts by weight of soap.

In the present invention, alpha sulfo acids are considered to be acidsnormally formed by the reaction of a saturated fatty acid with sulfurtrioxide in such a manner as to introduce an S0 group in the alphaposition on the hydrocarbon portion of the fatty chain. Withoutattempting to expand on the production of alpha sulfo fatty aclds whichis well covered both in patent and technical literature, it will sufiiceto describe the production of said sulfo acids only in general terms.

In those instances where it is preferred to eliminate coloring andsludge problems involved from sulfonating the unsaturated componentspresent in commercial fatty acids, substantially pure stearic acid maybe used. Sulfur trioxide is reacted with the acid while it is either ina fused state or in a solvent suspended state.

According to another prior art process, less expensive, commerciallyacceptable alpha sulfo fatty acids can be formed from a stearic acidcomposition known as rubber grade stearic acids. This composition, inaddition to containing between about 45 to 65 percent stearic acid, alsocontains lower fatty acids as well as about 5 to 10 percent unsaturatedacids. This prior art process consists of dissolving the fatty acidcomposition in a special class of solvents, introducing sulfur trioxide,preferably in combination with a diluent, for example, nitrogen or air,at a maximum temperature of C., preferably less than 30 C., andsubsequently heating the resulting reaction product at a temperatureless than about 100 C.

According to this prior art procedure, the initial product of thereaction between sulfur trioxide and the fatty acids is believed to bean acid sulfate or an acyl sulfuric acid of the fatty acid and sulfurictrioxide. When this intermediate reaction product is subsequently heatedat a temperature above 35 C., the alpha sulfo fatty acid is formed. Therate of formation of the sulfonated fatty acid depends upon thetemperature of the second heating step, the higher the temperature thefaster the formation. The initial heat treatment of less than 35 C. isrequired to reduce the tendency for the hydrocarbon solvents to undergosulfonation.

After formation, the sulfonated fatty acids may be separated from thesolvent, either by filtration or as a residue from distillation. Thesulfonated acid is then dissolved in water and neutralized to a desiredpH by the addition of an alkali, such as sodium hydroxide solution. Thisresults in the production of a mono-alkali salt, for example, themono-sodium salt of alpha sulfo stearic acid. Thus, normally only the SOH group is neutralized. The alkali salt suspension may then be heated toredissolve the salt and subsequently cooled to recrystallize and obtaina substantially pure mono-alkali salt of alpha sulfo fatty acid. A clearproduct, if the resultant product has a slightly tan appearance, may beobtained by using active charcoal and adding a bleaching agent, such assodium hypochloride or hydrogen peroxide, to the hot solution of theacid salt in the above process before recrystallization.

According to one reference, a special class of reaction solvents havebeen found to be quite effective for use in the sulfonation of the fattyacids. These special solvents are normally straight chain, saturatedhydrocarbons exemplified by hexane, heptane, octane, and even the lowerfraction such as propane of butane when used under pressure. As is wellknown, almost all the solvents normally used are susceptible in varyingdegrees to attack by the sulfur trioxide. Hence, the fatty acid isnormally suspended or completely dissolved in the solvent prior toreaction with the sulfur trioxide.

The alpha sulfonic acid derivatives of saturated fatty acids utilized inthis invention are those containing about 12 to 24 carbon atoms andinclude saturated fatty acids which contain substituents which do notaffect adversely the detergent and dispersing properties of the acid orits salts. While it is preferred to have the fatty acid in essentiallysaturated form, i.e., very little unsaturation, it should be noted thatin some instances commercial mixtures are quite adequate. Therefore,when suitable fatty acids are specified throughout the specification, itshould be understood that mixtures of saturated fatty acids as Well asmixtures of saturated and unsaturated fatty acids are contemplated.Examples of suitable fatty acids are stearic acid, palmitic acid,myristic acid, lauric, arachidic acid, and behenic acid. Of course,odd-numbered fatty acids, such as pentadecanoic acid, heptadecanoicacid, and nonadecanoic acid, may be utilized. The utilization of fattyacids derived from halogenated tallow and fatty acids derived fromtallow stearin are of particularly practical value from an economicstandpoint.

The salts of the alpha sulfo fatty acids may be alkali metal, alkalineearth metal, ammonium or lower monoor dialkyl amine salts wherein thealkyl group of the amine contains 1-4 carbons and may contain OH groups.Salts may be formed by the neutralization of the free acid. Particularlysuitable salts are the monoor di-salts wherein the cation is sodium,potassium, ammonium, magnesium, calcium, barium, lithium, etc. The saltsmay be formed by the simple replacement, i.e., metal above hydrogen onthe free acid, a metal plus salt reaction, or the commonly employeddouble decomposition reaction. When using one equivalent of metal peralpha sulfo carboxylic acid, generally only the SO H group isneutralized. Accordingly, when the mono-salt is mentioned throughout thespecification it is understood that the mono-salt is that saltneutralized only at the SO H group. Of course, in the di-salt, both thesulfo group and the carboxyl group are neutralized. Specific examples ofsulfo fatty acid salts suitable for use in the cleansing compositions ofthis invention are as follows: monosodium alpha sulfo stearic acid,monopotassium alpha sulfo stearic acid, monolithium alpha sulfo stearicacid, monosodium alpha sulfo myristic acid, monopotassium alpha sulfopalmitic acid, monolithium alpha sulfo arachidic acid, monosodium alphasulfo behenic acid, disodium alpha su'lfo stearic acid, dipotassiumalpha sulfo stearic acid, dilithium alpha sulfo stearic acid, as well asidentical salts substituting calcium, magnesium, barium, ammonium, etc.,for the above mentioned specific cations.

As discussed above, the ordinary soap, hard-water-sensitive detergent orsoap-sensitive detergent comprises the major amount of the cleansingcomposition. Since the production of soap is well known, a detailedanalysis of the definition of said soaps will not be set forth here.However, a general description of the soaps contemplated for use in thisinvention will be illustrated. Soluble soaps, by definition, are thesodium and potassium salts of the saturated fatty acids having fromabout 8 to about 24 carbon atoms. Those soaps containing the sodium ionare considered hard soaps while those with the potassium are called softas they are more Water-soluble than the former.

While soaps of other metals (copper, lead, mercury, zinc, and aluminum)have special uses, generally these soaps are not suitable for washing orcleansing purposes and are not considered to be included by the termsoluble soaps utilized throughout this specification. Since a highpercentage of saturated acids are desirable, beef and mutton tallow,palm oil, cocoanut oil, lard, hydrogenated vegetable or whale oils areutilized in the saponification process. The soap molecule has a longhydrocarbon chain and a polar carboxyl group. The hydrocarbon part has afatdissolving property while the carboxyl group is attracted and held bythe water.

The various types of detergents utilized in scouring pads is well knownand a detailed description is believed not to be warranted here.Generally speaking, however, the teachings of this invention areespecially directed to hardwater-sensitive detergents or soap-sensitivedetergents, i.e., those detergents that have an antagonistic elfect onsuds when in the presence of soaps. Hard-water-sensiti-ve detergents aregenerally of the polyglycol ester type with a substantial free fattyacid content. However, any detergent capable of forming water insolublecalcium salts in hard water can be considered hard-water-sensitive forthe purposes of this invention.

The following examples are presented to illustrate the invention. Itwill be understood that these examples are merely illustrative andshould not be taken in any manner as limiting the invention as definedin the appended claims.

EXAMPLE I Fifty parts by weight of water was poured into a conventionalsoap-mixing vessel. Thirty-five parts by weight of sodium tallow soapand parts by weight of the disodium salt of alpha sulfo stearic acidwere added and dispersed evenly throughout the solution. The mixture wasthen heated to a temperature of between about 145- 155 F. untilcompletely homogeneous. The mixture at this point was cloudy but quitefluid. A steel wool ball was impregnated by dipping in the solution. Theexcess cleansing material was removed by pressing, and the impregnatedpad was then dried in a conventional oven at about 200 F. The resultingscouring pad was found to not essentially affect the foaming of sudspresent on top of normally used dishwater. Further, there was noevidence of calcium salt curd formation.

EXAMPLE II Identical to Example I except that 52 parts by weight ofwater, 3 parts by weight of the dicalcium salt of alpha sulfo stearicacid and 45 parts of sodium tallow soap were utilized.

EXAMPLE III Seventy percent potassium vegetable oil soap, per centpotassium salt of alpha sulfo stearic acid, and 20 percent water wereutilized, and the procedure was the same as that described in Example Iexcept that the pad was freeze-dried.

EXAMPLE IV Forty parts sodium salt of dodecylbenzene sulfonic acid, 8parts of the sodium salt of alpha sulfo myristic acid, 20 parts ofsodium tallow soap, and 52 parts of water were utilized, and theprocedure was the same as that described in Example I.

EXAMPLE V Fifteen parts sodium salt of tetrapropylene sulfonic acid, 30parts of sodium tallow soap, percent parafiin wax, 8 sodium salt ofsulfo stearic acid, and 47 percent Water were utilized, and theprocedure was the same as that described in Example I.

EXAMPLE VI The cleansing compositions prepared in the above exampleswere used to impregnate steel wool, copper mesh and plastic meshscouring pads. In all instances, there was no visible effect on the foamof the synthetic dishwashing detergents when the scouring pads weredipped and utilized in the dishwashing composition. The steel woolutilized is that formed from fibrous steel which is commonly used forscouring purposes.

Coloring agents which give a pleasant color to the scouring pads may beutilized. Filler materials, such as gypsum, lava, silica, clay,nutshells, diatoms, etc., along with scouring or gritty materials may beutilized. Mold inhibitors, such as phenol, formaldehyde,pentachlorophenol, etc., as well as rust inhibitors which are known tobe effective for preventing the rusting of iron, may be utilized. Suchrust inhibitors include: borax, sodium carbonate, sodium chromate,sodium nitrate, sodium phosphate, etc.

Obviously, many modifications and variations of the invention as setforth herein may be made without departing from the spirit and scope ofthe invention, and, therefore, only such limitations should be imposedas are indicated in the appended claims.

We claim:

1. As an article of manufacture, an improved scouring pad impregnatedwith a cleansing composition containing water soluble soap and about 2%to about 25%, by weight, of an alpha sulfo member selected from thegroup consisting of alpha sulfo fatty acids, mono-salts of alpha sulfofatty acids, di-salts of alpha sulfo fatty acids, and mixtures thereof,said fatty acids having about 12 to about 24 carbons so that thescouring pad possesses non-defoaming of suds properties.

2. The article of claim 1 wherein the salts of the alpha sulfo fattyacids are alkali metal, alkaline earth, ammonium or lower monoor dialkylamine salts.

3. The article of claim 1 wherein the salt of the alpha sulfo fatty acidis an alkali metal or alkaline earth metal salt of an alpha sulfo fattyacid having an average of between about 16 to 18 carbons.

4. The article of claim 3 wherein the salt is a sodium salt of alphasulfo palmitic acid.

5. The article of claim 3 wherein the salt is a calcium salt of alphasulfo palmitic acid.

6. The article of claim 3 wherein the salt is a potassium salt of alphasulfo palmitic acid.

7. The article of claim 3 wherein the soap is a tallow soap.

References Cited UNITED STATES PATENTS 2,303,212 11/1942 Kise et al.252121 2,483,135 9/1949 Goldsmith et al. 25291 2,733,211 1/1956 Maxey eta1. 25291 2,867,586 1/1959 Weil et al 252-161 2,915,473 12/1959 Stirtonet al. 252161 3,219,584 11/1965 Stirton et al. 252161 3,293,684 12/1966Tundermann 15-104.94 3,377,289 4/1968 Stein et al 252161 LEON D. ROSDOL,Primary Examiner W. E. SCHULZ, Assistant Examiner U.S. Cl. X.R.15-40493; 134-6, 28, 40; 252--121

